1. Field of the Invention
The present invention relates to a premixed combustion gas burner having separated fire hole units, and more particularly, to a premixed combustion gas burner having separated fire hole units in which a total number of fire hole units formed on the surface of the burner are separated into several pieces in the premixed combustion gas burner having a tube-shaped burner and a plate-shaped burner which are separated from each other, and a cooling water tube penetrates a pin structure formed on the lower end of the plate-shaped burner, to thereby easily change the size and number of the fire hole units to easily change a total capacity of the burner, prevent deformation of the burner such as buckling due to thermal tension existing in the burner which may be caused by an excessive running of the burner and thermal expansion deformation, and play a role of making the water tube fixing the tube-shaped burner and the plate-shaped burner.
2. Description of the Related Art
As is well-known, a boiler for heating and supplying hot water for use in a general home, is divided into an oil boiler and a gas boiler, according to a fuel used. The oil boiler or the gas boiler uses a burner for burning oil or gas which is used in the boiler.
Thus, a general burner obtains heat by burning fuel safely and efficiently. According to the kind of fuel used, the burner is classified as either a gas burner for combustion of gas, an oil burner for combustion of liquid fuel such as kerosene or diesel oil, or a powdered coal burner for combustion of coal.
Additionally, the burner is divided into a premixed combustion burner and a diffusion combustion burner according to a method for mixing fuel and air. The premixed combustion burner burns fuel and air which have been mixed in advance. The diffusion combustion burner burns mixed fuel and air, the fuel and air are separately supplied to a burner and mixed therein.
However, the Bunsen gas burner has a long flame and a high flame temperature, thus needs more that an theoretical amount of air. Accordingly, there is an increase loss of heat due to high-temperature exhaust gas. This leads to an increased amount of pollutants such as NOx and CO. As a result, the Bunsen gas burner is somewhat limited in accomplishing maximum efficiency and reduction of pollutants in the gas burner equipment.
Also, a premixed combustion gas burner using knitted metal fiber mat of porous metal fiber weaving tissue which is used as a surface material of a combustion gas burner is used to reduce polluted materials such as NOx and CO and flame temperature. The knitted metal fiber mat of porous metal fiber weaving tissue which is used as a surface material of a combustion gas burner is woven like a fiber tissue with a metallic material of 50 μm or less in diameter. This is used as the surface material of the combustion gas burner to perform perfect combustion of inflammable premixed gas on the combustion surface, and then heat the combustion surface of the gas burner formed of the knitted metal fiber mat of metal fiber weaving tissue with the combustion heat. This thereby obtains a strong and uniform solid-state radiation energy from the combustion surface of the gas burner.
A loss of heat due to exhaust gas is reduced by reducing an amount of excessive air for combustion and lowering the temperature of combustion exhaust gas. This thereby provides an increase in thermal efficiency and suppresses pollutant materials such as NOx and CO that are discharged. Also, a range of a combustion load (a turndown ratio: TDR) is considerably wider than that of the general gas burners whose TDR is 5 to 1. Also, the stability of flame is remarkably superior to the that of the general gas burner and employs a simple structure. As described above, the knitted metal fiber mat of porous metal fiber weaving tissue is widely used as a combustion surface material for a gas burner for home use, commercial use and industrial use in order to enhance thermal efficiency and lower polluted materials in gas combustion equipment.
In particular, materials such as ceramic or stainless steel, and knitted metal fiber mat of porous metal fiber weaving tissue are used as a combustion surface material for a gas burner. Since the knitted metal fiber mat of porous metal fiber weaving tissue has a thermal treatment effect which lowers the temperature of the rear surface of the burner into an ignition temperature or less, it is known as a safe material having burner flames running few risk of backfiring through small holes on the knitted metal fiber mat of porous metal fiber weaving tissue, when the knitted metal fiber mat is used as the combustion surface material of the gas burner in order to perform combustion of the premixed gas. Thus, the gas burner using knitted metal fiber mat of porous metal fiber weaving tissue has an advantage of having no need to specially countermeasure a backfire phenomenon, which is used to reduce polluted materials such as NOx and CO and lower the temperature of flames.
However, in the case where the temperature of flames is low in the conventional premixed combustion gas burner, the burner flames may be unstable. This may raise the production cost and may make fabrication difficult. Also, it be difficult to stably control combustion of the premixed gas in home gas burner equipment which has a simple structure.
Also, in the case that ceramic, stainless steel, or knitted metal fiber mat of porous metal fiber weaving tissue is used as a combustion surface material of the premixed combustion gas slits, a premixer for premixing fuel gas and air may become large and somewhat complicated. As a result, the air blowing resistance increases due to a loss of pressure in the premixer and thus either abnormal noise may occur as part of a high-load region during combustion or main flames of the gas burner may be unstable.
As described above, in the case of the conventional premixed combustion gas burner, fire hole units forming a burner are formed on a single plate-shaped material or cylindrical vessel, or knitted as metal fiber. When fire hole units are formed on a single plate-shaped material or cylindrical vessel, the burner surface may be twisted due to thermal expansion. When metal fiber is used in a gas burner, the metal fiber is pulled and then assembled during assembling. Thereby, fire hole units are formed largely locally or in whole on the metal fiber, and thus cause scattering of the flames, which may cause flames to lack uniformity and a backfire to occur. Additionally, the conventional premixed combustion gas burner is expensive and difficult to fabricate.
In particular, the conventional premixed combustion gas burner having a tubular shape has downsides. Specifically, it is difficult to prevent deformation such as buckling due to either thermal tension at the time of an excessive running of the burner, damage by a fire of the burner surface due to overheat, or excessive production of nitrogen oxide due to heal.
Also, the conventional premixed combustion gas burner has a problem that it is difficult to mount a separate device such as a cooling water tube for cooling overheat of the burner.